When a woman squats down on your face and empties her bladder. Her ass cheeks will, if done appropriately, keep her urine out of your eyes just like a set of goggles would. Sometimes an enema might also be involved if you really love each other.
I was freaked when she wanted to do the Japanese RainGoggles on me, but it was totally worth it.
Specially designed goggles originating from Japan that allow the user to enjoy Golden Showers, Muddy Buddy and other such acts. They are also surprisingly useful for navigating through the annals of Urban Dictionary.
Lads, grab your Japanese RainGoggles, we're going to Shinjuku.
When a man puts his nose in a females vagina while she urinates/ejaculates causing him to squint and wish for protective eye wear. (i.e. swimming goggles)
Terra gave me japanese rain goggles and ruined my new silk duvet